This invention relates generally to closures, and more particularly to a blade for accordion-type metal storm shutters.
There are code requirements in Florida and other jurisdictions for storm shutters. The south Florida building code, applicable to Dade and Broward counties, specifies that storm shutters must be able to withstand the impact of a two-by-four, weighing nine pounds, moving at 50 feet per second, simulating the impact of debris during a hurricane. There are also standards for the ability to withstand wind pressure, including negative pressures, and fatigue loading tests. Many older steel roll shutters and the like are not capable of meeting these specifications.
Application No. 08/252,559 describes a shutter having plural extruded aluminum alloy blades. Neighboring blades are connected to one another by hinge members, each comprising a "socket" on one blade, and a "knuckle" on a neighboring blade, which fits within the socket. The blades are designed to limit hinging movement to about 90.degree., so that the angle between hinged blades is always acute. As a result, the shutter, when drawn, has a corrugated configuration that provides great strength.
This application discloses a modified form of the blade shown in the prior application. The modified blade is characterized by light weight, and a high strength-to-weight ratio.